The latest report by the Intergovernmental Panel on Climate Change has put out a blunt message: the world is perhaps three decades away from catastrophe. The panel says the world should not emit more than 1,445 billion tonnes of carbon dioxide if it has to have a good chance of keeping global warming below 2 degrees celsius. The current emission rate is around 50 billion tonnes a year. Work out the numbers.
Climate change sceptics may argue that the panel is being unnecessarily glum. But, even if we consider massive climate change to be an outlier, it is prudent to start thinking hard about it. The world increasingly appreciates the potency of black swans—low probability events that have a very high impact. Climate change is one.
There is a view that the frontlines of change will involve individuals, firms and cities. But it is hard to see how a global public good such as temperature stability can be ensured without agreements between governments.
